1. Field of the Invention
This invention is directed to a system which allows effective inventory control and extensive tracking capabilities of a plurality of articles by providing total real time access to a monitored locale in order to establish the existence, location and/or direction of movement of the articles. A plurality of tags are associated with the various articles being monitored, at least some of which include multi-frequency and uni-directional or multi-directional communication capabilities which at least partially serve to extend the operative range between the tags and a reader assembly in order to efficiently perform the monitoring procedure.
2. Description of the Related Art
The monitoring of a variety of different articles, products, etc. through the use of xe2x80x9ctagsxe2x80x9d secured to or otherwise associated with the various articles has been in use for many years. Moreover, various attempts to modify this type of tracking and inventory control have been made so as to adapt a tagging system for use in a variety of different applications. Such known applications include, but are not limited to, warehouses, retail outlets, industrial manufacturing sites, and almost any location where the variety or articles or products being monitored are manufactured, transported, stored, sold, etc.
In its more simplistic form, the tagging of articles has been associated with the display of pricing information in association with the shelving of various products, such as in retail outlets. Pricing and inventory controls are sometimes maintained through the inclusion of coded data on the tags, such as by means of bar codes, which are determinative of the identity, price, etc, of the various products. Initially, and as is currently being used, these types of xe2x80x9cshelf tagsxe2x80x9d have been simply constructed and include various information displayed thereon. Such displayed information, when coded as set forth above, can be read by various types of optical or digital scanners.
While shelf tags of the type set forth above are generally considered to be operative for less sophisticated applications, they are commonly recognized as being inefficient and cumbersome for use in many areas of commerce associated with the storage, transport, manufacture, etc, of various types of products or articles being monitored. As one example, the updating the information frequently requires complete replacement of the tags thereby at least partially defeating the goal of efficient inventory, tracking and pricing controls for which such systems were primarily intended.
To overcome the above noted problems associated with shelf tags, attempts have been made to develop more sophisticated electronic tags which are associated with some type of display facilities. Typically known electronic tags and their attendant systems, of the type referred to herein require the use of complicated circuitry and cooperative electronic control components in order to affect their installation and use. Another major draw back associated with devices of this type is that in order to maintain an efficient and accurate display a continuous supply of power must be maintained. The maintenance of such power is limited resulting in the limiting of information which can reasonably be displayed. Accordingly frequent replacement of the tags, associated power supplies, display facilities, etc, is the result.
In an effort to expand the versatility and efficiency of tracking and inventory control of a variety of articles, products, etc. and as a result of the problems and disadvantages of the type set forth above, associated industries have moved forward. Resulting advancements in this field has yielded the development and utilization of radio frequency (RF) tags and their attendant systems. In general, RF tags are capable of retaining and transmitting a substantial amount of information, all of which is required for the expansive tracking, security and inventory control requirements associated with modern day industrial, transport and retail facilities.
More specifically, the RF tag systems are capable of receiving and storing information in a read/write application as well as being capable of sending and/or receiving data relating to product identification, status, location and overall control. However, known or conventional RF tagging systems are recognized as having at least one primary disadvantage associated with limited communication range. Accordingly, in order that transmission of signals to one or more tags be accomplished for purposes of activation and/or data communication, an appropriate exciter/reader would have to be positioned in very close proximity to the one or more tags involved in the monitoring system. Therefore, the versatility and practical applications of such systems are severely limited due at least to the proximity or range restrictions associated therewith. Efficient monitoring of articles during product delivery, transportation, material handling, security tracking and large scale storage may not be possible. As a result, radio frequency tag technology has not enjoyed wide spread use in many industrial applications associated with the commercial development of various products.
Based on the above, there are still significant disadvantages and problems associated with known tagging systems especially when considering the wide variety of industrial applications where such systems could be effectively implemented. Accordingly, there is a significant and long recognized need for an improved tracking and/or inventory control system. Such an improved system should be capable of 100% real time inventory control as well as detecting the existence, location and direction of movement of an item. A plurality of RF tags associated with such an improved system could be further structured to detect tampering, low battery power, unauthorized movement and/or removal from the articles or products being monitored.
Such an improved system could also be adapted, without significant structural or operative modification, for usage in a variety of different areas including large scale warehousing, transport, delivery, retail inventory, pricing and security, theft prevention, all without significant manual intervention. In addition, other unique and/or customized features can be associated with the tags, dependent on the customer/user applications and requirements.
Accordingly, an improved system using multi frequency tags with strategically placed readers, accomplishing activation and/or powering of certain ones of the plurality of tags utilizing a higher level of power signal and prescribed frequency range would increase the reading or transmission distance associated with the tags thereby allowing such an improved system to overcome the recognized problems and disadvantages associated with RF tagging monitoring system of the type set forth above.
This invention is directed to a real time total asset vis-ability system which in practical application is manifested in a monitoring system for maintaining inventory control, on a real time basis, of a variety of articles and within a monitored local. For purposes of clarity, the terms xe2x80x9cmonitored localexe2x80x9d may assume a variety of different locations such as, but not limited to a warehouse, manufacturing or storage facility, transport and/or delivery vehicles, as well as a variety of retail facilities. In addition, the versatility of the monitoring system of the present invention can be used for inventory control as well as positional and movement tracking of various articles with minimal or no structural/operational modifications of the various operative components of which the system is comprised.
More specifically, the system of the present invention comprises a host controller which may be in the form of a computer/processor disposed in communicating relation at or remote from the locale being monitored. In addition, a reader assembly comprises, dependent upon the specific embodiment and practical application for which the system of the present invention is adapted, one or more readers. As will be explained in greater detail hereinafter, the reader assembly may comprise a variety of different types of readers structured to perform a variety of procedures for individually and collectively monitoring a plurality of radio frequency (RF) responsive tags. The tags are mounted on or otherwise directly associated with various articles being monitored. It is of course understood that the articles being monitored may of course vary greatly and are not limited to a specific class or category of objects, products, etc. Also the tags may be a part of or directly associated with xe2x80x9cpersonnel badgesxe2x80x9d for the location, identification, etc, of numerous authorized personnel which have access to the monitored locale and/or the plurality of articles stored within or passing into or out of the monitored locale.
It is also emphasized that the reader assembly may in certain applications comprise a plurality of readers disposed in a predetermined array throughout the locale being monitored, such as when such a plurality of readers are fixedly disposed within the locale. In other preferred embodiments of the subject monitoring system, as represented by various practical applications, the reader assembly may comprise a single reader or relatively few readers. In this latter application and by way of example only, the reader assembly may comprise one or more mobile or handheld readers which are movable about the monitored locale. The mobile/handheld readers thereby communicate with the plurality of tags for purposes of establishing the existence and/or identification of the various articles associated with the tags.
The plurality of monitoring tags may also vary in structure and function based on their intended operation and the practical application to which they are applied. In the various preferred embodiments of the present invention a common operative characteristic of at least some of the plurality of tags is the ability to establish uni-directional communication or transmission to the reader assembly. Further, each of the tags are pre-programmed to include identification or other pertinent data which enables the user or operator to determine the status of the plurality of articles. As a generally descriptive term, the status of a monitored article may comprise the determination of its existence, location, direction of travel, removal, etc. dependent on the requirements of the customer or user of the subject monitoring system.
By way of example, in its simplest form, one or more of the tags defining the tag assembly comprises a passive tag characterized by not having a self-contained power supply associated therewith. Moreover, the passive tags are powered by being exposed to and/or maintained within an electric field or exposed to an electric signal of a predetermined first frequency. Once powered and activated identification and/or pertinent data relating to inventory control and/or tracking is transmitted from the various passive tags (as well as the active tags to be described hereinafter) to an appropriate one or more readers servicing the monitored local. Once received, the data transmitted from the plurality of tags is then transmitted by the reader assembly to the host controller/processor. The data is further processed by the host controller as required to maintain the desired inventory and/or tracking controls. As will also be explained in greater detail hereinafter, communication or transmission from the tags to the reader assembly occurs at a second frequency, which differs from the aforementioned first frequency or activation and/or power-up frequency.
The tag assembly may also include one or more active tags which are distinguishable from the aforementioned passive tags by including a self-contained power source. As such, the active tags are pre-programmed to periodically transmit, on a pre-scheduled time basis, identification data or other appropriate information to one or more of the readers associated with the locale being monitored. Such active tags further include power supply detection capabilities which will communicate to the reader assembly the existence of a failing battery or a depleted power source. Both the passive and active tags are also structured to include numerous other operative features including tamper switches and locking devices particularly, but not exclusively, adapted for use in retail environments.
Further, both the passive and active tags may have common operative features such as multi-frequency capabilities wherein the activation or power-up field or signal is generated at the aforementioned first frequency and communication between the tag and the reader, either in a uni-directional or bi-directional mode, occurs at a second, differing frequency. The existence of the multi-frequency capabilities of the various tags enhances the range or proximity in which communication, activation, power-up, etc, may occur.
More specifically, FCC regulations prohibit the generation or transmission of pulsed signals, for example between a reader and a tag, except when licensing requirements are met. However FCC regulations do allow for the generation of fields/signals of certain frequencies, having pre-established band parameters, to be transmitted or generated at increased field strengths. Therefore, establishing a field strength of xe2x80x9cunlimited radiated energyxe2x80x9d within the frequency parameters specified is permitted. In other words, increased power can be utilized within certain in specified frequency ranges, including 13.56 MHz. to increase the range in which the tags of a monitoring system can be detected, activated, powered-up, etc. without violating FCC regulations. Accordingly, activation signals or the establishment of electric fields for the activation or xe2x80x9cwake-upxe2x80x9d and/or xe2x80x9cpower-upxe2x80x9d of one or a plurality of RF responsive tags can be accomplished using increased field strengths as long as there is no human exposure hazards involved. Therefore, utilizing the aforementioned first frequency in the frequency range of 13.56 MHz. allows for the activation and/or powering (such as in passive tags) at a much higher energy level so as to increase the read distance and/or proximity range to at least approximately 12 to 15 feet without violating any regulatory codes.
The aforementioned multi-frequency capabilities of the various types of tags (both active and passive) in the monitoring system of the present invention further provides for data transmission or communication between the tags and the reader assembly at a second frequency, which differs from the aforementioned first frequency. Further such data transmission normally occurs on a periodic pulsed basis, at pre-scheduled times, rather than as a continuously generated, high strength field or signal, at which the first frequency normally occurs. Also, in certain preferred embodiments to be described hereinafter, one or more of the plurality of tags are structured for asynchronous transmissions, at the second communication frequency, to the reader or host controller.